Need help with shaping a rehearsal "studio"

Hello from Finland. I have possibility to build small rehearsal space for my band. We would like also to track songs for now and then. Also mixing would take place in a same room. The room will be built in the back of work shop and there is a drain hole in the floor about three meters away from the back wall and it can't be covered. So I'll attach a picture where is three possible versions of room shape. I would be pleased if you can suggest acoustically best design of those three. By the way, the ceeling of the room is angled. Yours: Shakey